No, I am talking about the free living planarians, dugesia tigris (or something...) they are not parasites, but they are related to the parasite species, they are active preditors...
They are supposed to be one of the base species on this planet, most have not evolved...
If you cut one between the eyes, each one grows into a head, so you can make a 10 headed (all complete with brains/eyes/etc, they can regenerate into full worms after being cut into 10 different peices, and they are about an inch long, and are some of the oddest little creatures... But, no, not tapeworms or the like, just little flat worms... they are really neat.
Hope that clears things up
Dan Conner